need some inspiration on what to put in it. as in what kind of macro algea and other organisms and inverts.
Hmmm...well, I know you said it's for your 55G display, but how many gallons will the 'fuge be? As far as the macro, I'm a big fan of Chaetomorpha (the stuff that looks like brillo pad), but diversity is a good thing when it comes to 'fuges. You will find if you combine several different types, that some will overtake others, and you'll have to stay on top of pruning as they grow. As a side note, I'd recommend staying away from certain types of Caulerpa like grape...feather is fine, as are some others. Graceliaria is another great type of macro, and if you have a tang, it will enjoy eating this type of macro. I also like the Ulva, but it's not as easy to find in the LFSs as some of the others I've mentioned...Ulva is GREAT for breeding 'pods though!

OK...on to the "organisms" - bear in mind this is a place of refuse for 'pods and small organisims - so NO crabs or fish of any kind (they will eat the 'pods). We keep several smallish snails in ours to help keep the acrylic clean, the small white sand stars (which you'll frequently get with LS), amphipods, and mysis. Bristle worms usually end up in there too, but we didn't put them there on purpose...LOL...they're good though, so don't worry. Best thing to do would probably get smaller clumps of macro from several people's established 'fuges - this way, you will not only have diversity in your types of macro, but also with desired critters.

As far as the "bed" of your 'fuge - lots of options here. Some people prefer sand beds, some just with LR rubble, some like a mixture of 'fuge "mud" with LS. If you don't already have it, I highly recommend a book - "The Conscientious Marine Aquarist" by Robert Fenner. It is chock full of information, and has a nice section on refusiums and the options availb. to date. OR you can just plug in "marine refusium" on Google and read up - see what will come closest to matching your needs with your system. ;)

W.